Something I've noticed recently when browsing the jazz sections of record shops is the proliferation of sub-genres among the Japanese artists. Just hearing the names is enough to get a fan excited about the apparent explosion of creativity.
For example, postrock jazz acts such as Fox Capture Plan or Mouse On The Keys are clearly doing something innovative with a combination of lingering piano melodies laid over complex drum patterns — all of it played loud. However, that volume also leaves them sounding more like alternative-rock acts, which has sometimes left confused retailers putting them in both the rock and jazz divisions of their stores.
Similarly, the electro jazz of Tokyo Zawinul Bach explores new territory by blending elements of jazz, hip-hop and electronica to create a distinctive sound with a definite jazz feel.